1. Technical Field
The present invention relates to magnetic tape heads. More specifically, the present invention relates to controlling electrostatic discharge during tape head operation.
2. Description of Related Art
Electrostatic discharge events in tape recording heads occur typically with mishandling or in operation, when magnetic tape passes over the head. In both cases, a static charge is accumulated and then discharged through the read elements, which can result in serious damage to or destruction of the read elements.
Modern tape heads are particularly vulnerable to electrostatic discharge. As tape head designs move from insulating ferrite materials to conductive ceramic materials in the substrate and closure, the incidence of electrostatic buildup, and subsequent discharge, becomes greater. As the read elements on magnetic tape heads become smaller and more delicate, the effects of electrostatic discharge become more destructive. In addition, thin film shields used in the reader design offer less protection to the readers from electrostatic discharge.
In conventional tape head designs, each of the major components can be electrically isolated from the rest of the head, which will allow a static charge to accumulate. When the charge is high enough, it will discharge through the nearest available ground, typically the nearest read element. Therefore, a tape head design that controls electrostatic discharge, by allowing accumulated electrostatic charge to drain safely to ground without damaging the read elements, would be desirable.
The present invention provides an apparatus and method for controlling electrostatic discharge in magnetic tape heads. This method includes using a conductive adhesive to electrically connect the substrate and closure of each read/write module as well as connect the read/write modules in the head. The conductive adhesive can be used as an adjunct to or a replacement for adhesives used during the normal assembly process. The modules are then connected to ground. In one embodiment, the read modules are tied to the write module, which is then connected to ground through a high resistance path.